Floating drive assembly for an automotive cooling fan

ABSTRACT

An assembly (12) for moving air through a heat exchanger (10) comprising a shroud (14) for mating with a heat exchanger (10) and a fan (20) disposed in the rear opening (18) of the shroud (14). The fan (20) comprises a hub (22) having an axis (A) and blades (24) extending radially from the hub (22) to distal ends for moving air through the shroud (14). The assembly is characterized by a floating drive assembly (52, 54, 56) including an inner drive member (64), an outer drive member (68, 70), and a flexible transmission (74, 75) interconnecting the members for rotating the drive members together while allowing relative radial movement between the drive members as the drive members rotate the fan (20). A bearing ring mechanism (28, 30) interconnects the distal ends of the blades (24) and the shroud (14) for rotatably supporting the fan (20) solely by the shroud (14). The bearing ring mechanism (28, 30) includes a ring (28) surrounding and interconnecting the distal ends of the fan blades (24) a guideway (30) in the shroud (14) supporting and retaining a head (32) extending from the ring (28) for rotation relative to the shroud (14).

TECHNICAL FIELD

The subject invention relates to automotive vehicle cooling and, moreparticularly, to the drive mechanism for rotating the fan in a shroudfor directing air through an adjacent heat exchanger.

BACKGROUND OF THE INVENTION

Automotive vehicles are powered by liquid cooled engines. The liquid iscooled by being circulated through a heat exchanger. The heat exchangertransfers heat from the liquid to air passing through the heatexchanger. The air is moved through the heat exchanger by a fan. Inorder to maximize the air flow through the heat exchanger to maximizethe capacity to withdraw heat from the liquid, a cowling or shroudsurrounds the fan and the heat exchanger. It is the objective of theshroud to prevent leakage of air around the heat exchanger, i.e., toprevent leakage and make sure all of the air moved by the fan movesthrough the heat exchanger.

The fan includes a plurality of radially extending blades with thedistal ends of the blades adjacent the shroud. There have been variousdevelopments for reducing the leakage between the distal ends of the fanblades and the shroud. The U.S. Pat. No. 3,680,977 to Rabouyt et aldiscloses elastic seals and U.S. Pat. No. 3,842,902 to Poslusnydiscloses a combination of labyrinthine seals while U.S. Pat. No.5,183,382 discloses a combination of elastic or flexible members in alabyrinth-type seal combination. On the other hand, the U.S. Pat. No.5,342,173 to Vera discloses a profiled annular hoop at the distal endsof the fan blades for aerodynamically controlling air flow. However, allsuch combinations require a radial tolerance between the tips of the fanblades and the shroud which is sufficient to allow relative radialmovement between the tips of the fan blades and the shroud. Thistolerance is necessary because the fan is typically rotated by thevehicle engine which vibrates and moves radially relative to the axis ofrotation of the fan. In order to diminish the transmission of suchvibratory motion from the engine to the fan, various drive mechanismshave been utilized. Such a system is disclosed in U.S. Pat. Nos.4,376,424 and 4,445,583 to Mazur wherein the belt entrained about thedrive pulleys between the engine and the fan is placed in tension by aspring loaded idler pulley. Although belt tensioning systems are knownwhich employ concentric orbiting members, as illustrated in JapanesePatent 149440 dated Jun. 26, 1991, none have employed for automotivecooling systems and there remains a need for improved designs.

SUMMARY OF THE INVENTION

An assembly for moving air through a heat exchanger comprising a shroudpresenting a front opening for mating with a heat exchanger andpresenting a rear opening with a fan disposed in the rear opening of theshroud. The fan includes a hub having an axis and blades extendingradially from the hub to distal ends for moving air through the shroud.A drive assembly is operatively connected to the fan for rotating thefan relative to the shroud. The assembly is characterized by the driveassembly including an inner drive member, an outer drive member, and aresilient element interconnecting the members for rotating the drivemembers together while allowing relative radial movement between thedrive members as the drive members rotate the fan.

BRIEF DESCRIPTION OF THE DRAWINGS

Other advantages of the present invention will be readily appreciated asthe same becomes better understood by reference to the followingdetailed description when considered in connection with the accompanyingdrawings wherein:

FIG. 1 is an exploded perspective view of an assembly constructed inaccordance with the invention;

FIG. 2 is a schematic side view partially broken away and in crosssection;

FIG. 3 is a view taken substantially along line 3--3 of FIG. 2;

FIG. 4 is a cross sectional view of the drive assembly;

FIG. 5 is a cross sectional view of the floating drive member of thesubject invention;

FIG. 6 is a view like FIG. 2 but showing an alternative embodiment;

FIG. 7 is a view taken substantially along line 7--7 of FIG. 6;

FIGS. 8 through 11 are fragmentary cross sectional views of variousembodiments of the bearing ring mechanism interconnecting the distalends of the blades.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the Figures, wherein like numerals indicate like orcorresponding parts throughout the several views, an assembly for movingair through a heat exchanger, generally shown at 10, is generally shownat 12. The assembly 12 includes a shroud 14 presenting a front opening16 for mating with the heat exchanger 10 and presenting a rear opening18. The assembly 12 also includes a fan 20 disposed in the rear opening18 and comprising a hub 22 having an axis A and blades 24 extendingradially from the hub 22 to distal ends 26 (shown in FIG. 1) for movingair through the shroud 14.

The assembly 12 is characterized by a bearing ring mechanism 28, 30interconnecting the distal ends 26 of the blades 24 and the shroud 14for rotatably supporting the fan 20 solely by the shroud 14. The bearingring mechanism 28, 30 includes a ring 28 surrounding and interconnectingthe distal ends 26 of the fan blades 24 and a guideway 30 supporting andretaining the ring 28 for rotation relative to the shroud 14. The ring28 defines a head 32 as viewed in cross section and the guideway 30embraces the head 32. As illustrated in FIGS. 8 through 11, the ring 28also defines a web 34 extending radially as viewed in cross section tosupport the head. The web 34 is more narrow in the axial direction thanthe head and the guideway 30 embraces the head adjacent each side of theweb 34 to underlie the head. In other words, the guideway 30 is C-shapedto encircle the head with the web 34 extending through the opening ofthe C-shape.

Various alternative constructions of the head 32 and guideway 30 areillustrated in FIGS. 8 through 11. In FIG. 8, the head 32a has aspherical shape as viewed in cross section and the guideway is definedby two components 30a and 30b and a connection bolt 36 for connectingthe components 30a and 30b together to embrace the spherical head 32a.In FIG. 9, the head 32b has a rectangular shape as viewed in crosssection and the guideway is defined by two components 30c and 30d andconnection adhesive connects the components 30c and 30d together toembrace the rectangular head 32b. In FIG. 10, the head 32c has arectangular shape as viewed in cross section and the guideway is definedby two components 30e and 30f and a connection bolt 38 connects thecomponents 30e and 30d together to embrace the rectangular head 32c. Inaddition, a plurality of bearings 40 are disposed between the flanges ofthe head 32c and the lips of the guideway as defined by the components30e and 30d thereof. In FIG. 11, the head 32d has a triangular shape asviewed in cross section and the guideway is defined by two integralcomponents 30g and 30h and the terminal component 30h is wrapped aroundthe head 32d for connecting the guideway 30a and 30b to the triangularhead 32d.

The assembly 12 also includes a floating drive assembly operativelyconnected to the fan 20 for rotating the fan 20 relative to the shroud14 while allowing relative radial movement between the drive assemblyand the axis A of the hub 22 to accommodate relative movement betweenthe drive assembly and the fan 20 as the drive assembly rotates the fan20.

In the embodiment of FIG. 2, the drive assembly transmits power from anautomotive engine 42 to the fan 20. An automotive vehicle includes aframe 44 and the engine 42 is supported on the frame 44 by motor mounts46 for vibrational type movement relative thereto, as is well known inthe art. The heat exchanger 10 is supported by the frame 44 throughbracket 48 adjacent the heat exchanger 10 for directing air through theheat exchanger. Actually, the shroud 14 has side flanges 50 (FIG. 1)which are bolted or otherwise secured to the sides of the heat exchanger10 for engaging the front opening 16 of the shroud 14 in air tightrelationship with the heat exchanger. As is well known, the enginevibrates or otherwise racks and moves relative to the frame 44 andconsequently the heat exchanger 10 and shroud 14. The motor mounts 46are made of resilient material to accommodate such relative movement.

The subject invention provides a drive assembly which allows relativemovement between the drive input and the fan 20. Such a drive assemblyallows the elimination of the gap between the tips of the fan blades andthe shroud, which, in turn, to prevent air leakage around the tips ofthe fan blades. The hub 22 is keyed to and driven by a shaft 50, whichis, in turn, rotated by the pulley 52. A drive belt 54 is entrainedaround the pulley 52 and a floating pulley 56. In the embodiment ofFIGS. 2 and 3, the floating pulley 56 is keyed to and rotated by theshaft 58 which is rotated by the engine 46, i.e., the drive assemblyoperatively interconnects the engine 46 and the fan 20 to accommodatethe vibrational type movement of the engine 46 relative to the fan 20.In the embodiment of FIGS. 6 and 7, the floating pulley 56 is keyed toand rotated by a shaft which is rotated by an electric motor 60. Theelectric motor 60 is supported by the shroud 14 via a bracket 62 whichbolted or glued to support structure, such as the vehicle frame 44 orthe shroud 14.

The floating pulley is generally indicated at 56 in FIGS. 4 and 5 and ischaracterized by including an inner drive member 64 keyed to a shaft 66and a two component outer drive member 68, 70. The outer drive membercomprises a primary component 68 which includes a belt receiving annularpulley ring extending around and in radially spaced relationship to theperiphery of the inner drive member 64. A flange extends radiallyinwardly from the annular pulley ring to slidably engage the side of theinner drive member 64. A secondary component 70 of the outer drivemember comprises a disc secured with fasteners 72 to the open side ofthe annular pulley ring to slidably engage the other side of the innerdrive member 64. Accordingly, the inner drive member 64 is disposed andretained between the radially inwardly extending flanges of the outerdrive member 68, 70. A flexible transmission component interconnects theinner 64 and outer 68 drive members for rotating the drive memberstogether while allowing relative radial movement between the drivemembers as the drive members rotate the fan. The flexible transmissioncomponent is based upon a resilient or flexible element disposed betweenthe inner 64 and outer 68, 70 drive members. As illustrated, thatresilient or flexible component is defined by a plurality of springs 74which are disposed between the shaft 66 and an annular collar 77extending axially from the disc component 70. Alternatively or inaddition, an elastic material 75 may be disposed in the radial spacebetween the periphery of the inner drive member 64 and the inside of theannular pulley ring of the primary component 68 of the outer drivemember. The inner drive member 64 has a plurality of holes 76 extendingtherethrough from side to side and pins 78 are supported between theside flange of the primary component 68 and the secondary disc component70 to extend through the holes 76. Accordingly, the outer drive member68, 70 may orbit in a vertical plane relative to the inner drive member64. Therefore, the resilient or flexible connection, through the springs74 rotates the drive members 64 and 68, 70 together while allowingrelative radial, i.e., orbital or offset, movement between the drivemembers as the drive members rotate the fan 20.

Accordingly, the drive assembly includes a drive shaft 66 and the innerdrive member 64 comprises a wheel keyed to the drive shaft 66 forrotation therewith and presenting opposite sides and an outer periphery.The outer drive member 68, 70 includes an annular ring extending aroundand in radially spaced relationship to the periphery of the inner drivemember 64 to allow relative orbital movement between the drive members.The plurality of springs defining the resilient transmission 74 aredisposed to extend radially between the drive shaft 66 and the annularring of the outer drive member 68, 70. The organic polymeric materialwhich is elastic and defines the resilient transmission 75 is disposedannularly between the periphery of the wheel of the inner drive memberand the annular ring of the outer drive member 68, 70.

Said another way, a pair of disc-like elements extend radially along thesides of the wheel of the inner drive member 64 from the annular ring ofthe outer drive member 68, 70. And at least one of the disc-likeelements is an independent component 70 of the outer drive member and isremovably connected via the bolts 72 to the annular ring of the outerdrive member 68, 70. The plurality of holes 76 extending between thesides of the wheel of the inner drive member 64 and the pins 78extending between the disc-like elements of the outer drive member 68,70 and through the holes 76 define limiting means for limiting thedegree of the relative orbital movement.

The invention has been described in an illustrative manner, and it is tobe understood that the terminology which has been used is intended to bein the nature of words of description rather than of limitation.

Obviously, many modifications and variations of the present inventionare possible in light of the above teachings. It is, therefore, to beunderstood that within the scope of the appended claims, whereinreference numerals are merely for convenience and are not to be in anyway limiting, the invention may be practiced otherwise than asspecifically described.

What is claimed is:
 1. An assembly for moving air comprising:a shroud(14) presenting a front opening (16) for mating with a heat exchanger(10) and presenting a rear opening (18); a fan (20) disposed in saidrear opening (18) comprising a hub (22) having an axis (A) and blades(24) extending radially from said hub (22) to distal ends for moving airthrough said shroud (14); a drive assembly (52, 54, 56) operativelyconnected to said fan (20) for rotating said fan (20) relative to saidshroud (14); said assembly characterized by said drive assembly (52, 54,56) including an inner drive member (64), an outer drive member (68,70), and a resilient element (74, 75) interconnecting said members forrotating said drive members together while allowing relative radialmovement between said drive members as said drive members rotate saidfan (20); a drive shaft (66), said inner drive member (64) comprising awheel keyed to said drive shaft (66) for rotation therewith andpresenting opposite sides and an outer periphery, said outer drivemember (68, 70) including an annular ring extending around and inradially spaced relationship to said periphery of said inner drivemember (64) to allow relative orbital movement between said drivemembers; and wherein said resilient element (74) comprises a spring. 2.An assembly for moving air comprising:a shroud (14) presenting a frontopening (16) for mating with a heat exchanger (10) and presenting a rearopening (18); a fan (20) disposed in said rear opening (18) comprising ahub (22) having an axis (A) and blades (24) extending radially from saidhub (22) to distal ends for moving air through said shroud (14); a driveassembly (52, 54, 56) operatively connected to said fan (20) forrotating said fan (20) relative to said shroud (14); said assemblycharacterized by said drive assembly (52, 54, 56) including an innerdrive member (64), an outer drive member (68, 70), and a resilientelement (74, 75) interconnecting said members for rotating said drivemembers together while allowing relative radial movement between saiddrive members as said drive members rotate said fan (20); a drive shaft(66), said inner drive member (64) comprising a wheel keyed to saiddrive shaft (66) for rotation therewith and presenting opposite sidesand an outer periphery, said outer drive member (68, 70) including anannular ring extending around and in radially spaced relationship tosaid periphery of said inner drive member (64) to allow relative orbitalmovement between said drive members; and including a pair of disc-likeelements extending radially along said sides of said wheel of said innerdrive member (64) from said annular ring of said outer drive member (68,70).
 3. An assembly as set forth in claim 2 wherein one of saiddisc-like elements is an independent component of said outer drivemember and is removably connected (72) to said annular ring of saidouter drive member (68, 70).
 4. An assembly for moving air comprising:ashroud (14) presenting a front opening (16) for mating with a heatexchanger (10) and presenting a rear opening (18); a fan (20) disposedin said rear opening (18) comprising a hub (22) having an axis (A) andblades (24) extending radially from said hub (22) to distal ends formoving air through said shroud (14); a drive assembly (52, 54, 56)operatively connected to said fan (20) for rotating said fan (20)relative to said shroud (14); said assembly characterized by said driveassembly (52, 54, 56) including an inner drive member (64), an outerdrive member (68, 70), and a resilient element (74, 75) interconnectingsaid members for rotating said drive members together while allowingrelative radial movement between said drive members as said drivemembers rotate said fan (20); a drive shaft (66), said inner drivemember (64) comprising a wheel keyed to said drive shaft (66) forrotation therewith and presenting opposite sides and an outer periphery,said outer drive member (68, 70) including an annular ring extendingaround and in radially spaced relationship to said periphery of saidinner drive member (64) to allow relative orbital movement between saiddrive members; and including limiting means (76, 78) for limiting thedegree of said relative orbital movement.
 5. An assembly as set forth inclaim 4 wherein said resilient element (74) is disposed between saiddrive shaft (66) and said annular ring of said outer drive member (68,70).
 6. An assembly as set forth in claim 4 wherein said resilientelement (75) comprises an elastic material.
 7. An assembly as set forthin claim 4 including a pair of disc-like elements extending radiallyalong said sides of said wheel of said inner drive member (64) from saidannular ring of said outer drive member (68, 70) and wherein saidlimiting means comprises a plurality of holes (76) extending betweensaid sides of said wheel of said inner drive member (64) and a pin (78)extending between said disc-like elements of said outer drive member(68, 70) and through each of said holes (76).
 8. An assembly as setforth in claim 4 wherein said drive assembly (52, 54, 56) includes apulley (52) and a belt entrained about said pulley (52).
 9. An assemblyas set forth in claim 8 wherein said pulley (52) is in drivingengagement (50) with said fan (20).